I built my people door from doubled up 1x4s with hardware cloth sandwiched in between. I just realized I have no pictures of that on the member page. It's dark out now but will take a pic tomorrow and post. I also have a latch with a wire pin that I don't think raccoons could open. Also made sure there were no gaps below or to the sides that something could get their claws around. The door opens inward. It's been my experience that this is better to keep the chickens in when we enter (not foolproof, but almost). The chickens will be all plastered onto the door when we approach and gently pushing the door inward will usually push them away from the opening. Although I sometimes have one that slips through my legs, the times that happened they were so paralyzed by panic of "being outside the run OMG". that I could easily pick them up and put them back in.
I ran the HC on the sides of the run about 18 inches horizontally after it hit the ground. So it's one piece coming from the run wall, extending 18" (about) horizontally. I weighted it down with rocks and now there is a big load of leaves on top of it. The idea was that digging critters start digging near the fence line itself and if they hit the HC don't think to back up and tunnel. Here's a pic where you can sort of see that:

Digging it in a foot deep is probably a better bet, but I live on top of a mountain and the thought of having to dig a foot deep trench to bury the HC was just inconceivable. I have not noticed anything digging yet. Except the chickens who are determined to dig their way to Australia. I shouldn't have gotten Australorps! They're homesick. 
We have recently spotted a black bear, so I have now surrounded the entire "compound" with electronetting that has a 8K volt discharge when touched. I have no doubts that a bear could tear its way into the coop and run without much problems; it is impossible to build for that with wood.
Edited by fiddlebanshee - 4/13/12 at 5:23pm